linux_dsm_epyc7002/include/linux/userfaultfd_k.h
Kirill A. Shutemov bae473a423 mm: introduce fault_env
The idea borrowed from Peter's patch from patchset on speculative page
faults[1]:

Instead of passing around the endless list of function arguments,
replace the lot with a single structure so we can change context without
endless function signature changes.

The changes are mostly mechanical with exception of faultaround code:
filemap_map_pages() got reworked a bit.

This patch is preparation for the next one.

[1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org

Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00

82 lines
2.0 KiB
C

/*
* include/linux/userfaultfd_k.h
*
* Copyright (C) 2015 Red Hat, Inc.
*
*/
#ifndef _LINUX_USERFAULTFD_K_H
#define _LINUX_USERFAULTFD_K_H
#ifdef CONFIG_USERFAULTFD
#include <linux/userfaultfd.h> /* linux/include/uapi/linux/userfaultfd.h */
#include <linux/fcntl.h>
/*
* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
* new flags, since they might collide with O_* ones. We want
* to re-use O_* flags that couldn't possibly have a meaning
* from userfaultfd, in order to leave a free define-space for
* shared O_* flags.
*/
#define UFFD_CLOEXEC O_CLOEXEC
#define UFFD_NONBLOCK O_NONBLOCK
#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)
extern int handle_userfault(struct fault_env *fe, unsigned long reason);
extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
unsigned long src_start, unsigned long len);
extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
unsigned long dst_start,
unsigned long len);
/* mm helpers */
static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
struct vm_userfaultfd_ctx vm_ctx)
{
return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
}
static inline bool userfaultfd_missing(struct vm_area_struct *vma)
{
return vma->vm_flags & VM_UFFD_MISSING;
}
static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
}
#else /* CONFIG_USERFAULTFD */
/* mm helpers */
static inline int handle_userfault(struct fault_env *fe, unsigned long reason)
{
return VM_FAULT_SIGBUS;
}
static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
struct vm_userfaultfd_ctx vm_ctx)
{
return true;
}
static inline bool userfaultfd_missing(struct vm_area_struct *vma)
{
return false;
}
static inline bool userfaultfd_armed(struct vm_area_struct *vma)
{
return false;
}
#endif /* CONFIG_USERFAULTFD */
#endif /* _LINUX_USERFAULTFD_K_H */